Lecture 1: Nucleic Acids Flashcards
(44 cards)
_____: Functional unit of genetic information
gene
______: Total complement of genetic elements for an organism
genome
_______: include DNA and RNA
nucleic acids
______: Large molecules that carry genetic
information like chromosomes and plasmids
genetic elements
what is the central dogma?
DNA, RNA and protein together comprise
the genetic information flow
replication, transcription, translation
genetic information flow:
1) ______: DNA is duplicated
2) _______: information from DNA
is copied into RNA
i. mRNA (messenger RNA):
encodes protein
ii. tRNA (transfer RNA): plays role
in protein synthesis
iii. rRNA (ribosomal RNA): plays
role in protein synthesis
3) _______: information in mRNA is
used to build proteins
Replication
Transcription
Translation
_______ = pentose sugar and nitrogenous base only (no phosphate group)
Nucleoside
nucleic acids are…
DNA = deoxyribonucleic acid
RNA = ribonucleic acid
monomers of nucleic acids are…
nucleotides
a nucleotide has three components, what are they?
pentose sugar (ribose in RNA and deoxyribose in DNA)
nitrogenous base
phosphate group
Difference between deoxyribose and
ribose is….
the presence of OH on 2’-
carbon in ribose pentose sugar
where do the phosphates connect in the backbone?
3′ carbon of one
sugar to 5′ carbon of the adjacent sugar
what are the nitrogenous bases in DNA
A, C, G, T
what are the nitrogenous bases in RNA
A, C, G, U
T/F: Primed numbering on pentose sugar differentiates from the
numbering on nitrogenous base
true
Can there be more than one phosphate group
attached to a nucleoside?
yes! nucleoside ____phosphate
mono, di, tri, etc.
_____: Devised three-
dimensional ball-and-
stick models to deduce
the structure of folded
protein → alpha helix
* Provided 1st clue
Linus Pauling
chemist and 1954 Nobel Prize winner
______ and ______:
Subjected crystallized DNA to X-ray beam
* Spacing of atoms within crystal
determines diffraction pattern
* Diffraction pattern mathematically
interpreted to provide structure
* Helical structure (10 bp/turn)
* Too wide for one helix
* Provided 2nd clue
rosalind franklin and maurice wilkins
______:
Analyzed the base composition of DNA in the effort to find clues to
the structure of DNA
Extracted the chromosomal DNA
Added protease to remove protein
Acid-treated the DNA to hydrolyze the bases from DNA strands
Subjected isolated bases to paper chromatography
Extract bands and determine amount by light spectroscopy
erwin chargaff
what is chargaff’s rule?
The amount of adenine (A) is equal to thymine (T)
* The amount of guanine (G) is equal to cytosine (C)
* Provided 3rd clue
______:
Attempted to build models based on the
scientific clues of DNA
* Paralleled backbones of two helices on outside
with like bases aligned BUT didn’t fit model
* Revised model by aligning bases A’s to T’s and
G’s to C’s as per Chargaff’s rule
james watson and francis crick
what is the conservative model of DNA?
Complementary strands are synthesized
from parental “old” templates
* The two newly created “daughter” strands
than come together
* The parental strands re-associate
fully conserve OG DNA
what is the dispersive model?
Parental strands are dispersed into two new
double helices following replication
* Each strand consists of both old and new
DNA
* Would involve cleavage of the parental
strands during replication
mixed together on each strand
what is the semi-conservative model?
Each parental “old” strand serves as a
template for synthesis of “new” daughter
DNA strand
* New DNA contains one parental strand
and one daughter strand
the right one!
